A portable information device, such as a tablet computer or a smartphone, typically includes a touch-screen liquid crystal display but not a physical keyboard. The display of the portable information device of this type is desirably larger in size for use, but a smaller display is desired when carrying it. To this end, a portable information device including a flexible display, such as an organic Electro Luminescence (EL), is designed. With this type of portable information device, not only a chassis but also the display can be folded.
The radius of curvature of such a flexible display is specified as a limit of the folding to keep its mechanical integrity. Thus, the portable information device requires a large space to allow the display to move up and down above the inner faces of the chassis during opening and closing of the chassis. This means that the thickness of the chassis would increase, and the space between the rear face of the display and the inner faces of the chassis would become a dead space. As a result, the space cannot be used effectively.
Consequently, it would be preferable to provide a thin chassis and space inside of the chassis for a portable information device having a foldable display.